Archive | November, 2017

Filament review: ColorFabb PLA-PHA variables

23 Dec

Filament review: ColorFabb PLA-PHA variables

This is the filament I have the most experience with, on both good and bad. I purchased my first rolls 1.5 years ago. I had worked really hard for a long time and thought that I would reward myself with some prime quality filament so I stocked up on 10 rolls of all the colors I wanted!

Up until buying from ColorFabb, I had only used filament from high quality vendors like Faberdashery, Diamond Age and Ultimachine. Given all the positive comments I'd seen from others I expected the same (or maybe even better?) from this Dutch vendor. I was wrong. Months of clogged extruders ensued.

The cost of troubleshooting

I purchased spare parts for several hundred Euros from Ultimaker, just so I could exclude that as being the problem. I practically rebuilt the entire extrusion system without being able to solve the clogs. I even went as far to buy a proper Fluke HWAC multimeter so that I could measure temperatures properly. I also incorrectly blamed Ultimaker & Cura for some of the issues hmmm

Tons of tests...

I eventually came down to the conclusion that the clogs came from inconsistent diameters (sometimes above 3mm, far from 2.85mm) and very varying quality of the plastic. For most plugs I'd find some black thing at the nozzle tip while cleaning it out. I should point out that cleaning out an ultimaker isn't very simple as you'll often have to disassemble half the print head. Not a fun task to do several times a day, especially since I also printed 800+ meters of Faberdashery plastic on the same printer without a single filament error...

Replacement rolls

I wrote several polite emails with the support crew at ColorFabb and I have to say their support is really stellar. Nothing to complain about there. They told me that both the formulation & diameter had been off on several of the early rolls, and offered to replace all my rolls with new filament at no cost. That's pretty good service?

Problem was - when I got the rolls, some of them were better but by no means all. Argh... I've paid almost 450 EUR for those rolls, I have to make them work! After a lot of testing & rebuilds of extrusion system on my Ultimaker, I came to the conclusion that the only way I could print with them was going far above the recommended 210C. Even then it would clog now and then if I tried to go too fast. Others at my hackerspace had similar experiences, but a friend using 1.75mm Colorfabb filament never has issues? My Ultimaker Original is equipped with a 100% original extrusion system and the only speciality is the added dual extruder & heated bed. None of these should have any effect on the printing.

New printer, new problems

I solved most my ColorFabb problems by printing really hot and cooling the Ultimaker hotend down with an extra fan as I printed. If I tried to go anywhere near their official recommendation, the printer would clog right away. This worked so well that when I built my new printer, I was completely flabbergasted when I got similar problems here. The new printer had an E3D hotend that I had heard tons of positive feedback on. As soon as I added ColorFabb's PLA/PHA, the printer choked unless I printed at 20-30C above the recommendation.

After a month of trying to solve the problem without using extra heat, I gave up. I then realised that my roll of Ultra Marine Blue didn't have a consistent color? The color varied quite a bit along the roll. I contacted ColorFabb and yet again they replaced the roll. Excellent service, and this time half the roll have printed nicely. Strange?

Tangles! I never had that with any other vendor of plastic on spools hmmm

The PLA / PHA combo has major differences from other vendors. One is the addition of PHA, another bioplastic. It is apparently this that gives this PLA it's shine and makes it less brittle than other PLA. I'm by no means an expert on bioplastics, but there is something that makes this PLA/PHA mix more prone to stick to the inside walls of the extruder. Most often, you'll pull this buildup out with the filament after a blockage, but some will remain and must be removed with the "Atomic pull" method.

I've learned that most industry players use PLA from NatureWorks. ColorFabb buys their PLA from FKuR Kunststoff in Germany. I dunno what to say other than that it has some other (and less desirable) properties than the NatureWorks PLA. ColorFabb did however tell me that they only use NatureWorks PLA in their transparent PLA filaments and sure enough - it performs a lot better.

Colorfabb's response

ColorFabb says that the printer settings may vary (even among the same model) and that their recommendations can't work for everyone. I must say that I find frustrating to hear that from a vendor when all my 3 printers (PrintbotJr, Ultimaker Original, BAMM) as well as friends printers need to go to the same high temperatures to extrude it well. What makes this even more frustrating is that companies like MadeSolid publish guidelines for lots of printers and these worked for me right away?

I am now printing successfully with PETG from MadeSolid, PLA from Faberdashery, some really old ABS from Makerbot (back when they made 3mm filament), ABS from Protoparadigm, Proto-pasta's carbon fibre infused PLA, 2 year old PLA from Diamond Age, NinjaFlex, PLA/ABS/flexible rubber from PlastInk, PLA from Ultimaker and even Taulman 618/645 Nylon. Not a single blockage with any of these, but as soon as I insert the PLA/PHA mix from Colorfabb, my extruder will clog up. How fast this happens will vary, but I can't trust it for longer prints.

I just had to throw away two entire rolls of white PLA/PHA since the quality was so inconsistent that the layer height varied so much it was clearly visible (see below). Printing the same object with the same settings using Silver colored Ultimaker PLA gives me excellent looking results:

They're so different that you'd think it was printed on two different printers? This really is a shame as my two black rolls of PLA/PHA (made the same month!) will produce great looking results, even at fairly low temperatures???

I have completely given up on ColorFabb and it's a shame as they make so many cool things such as WoodFill, CopperFill & BronceFill. I just can't afford to spend more time on it as I've easily spent more than 100 hours cleaning out nozzles, solving clogs and failed prints. That's bad for business and not what I'd call "production quality". It's simply too inconsistent. I have a "trick" of working with it that "sort of" works and that's doing 5-6 atomic pull's with Taulman 645 Nylon before anything more than tiny prints. I'm also printing at speeds far higher than I like (due to the mass of the 30x30cm heated bed). This causes bandings in the prints, but then at least I can use the filament rather than just throw it away. It'll still get me plenty of jammed nozzles though.

Since MadeSolid now sells 15 different colors, so I'll get my PETG from them instead. As for PLA - rumours say that Faberdashery will soon begin shipping their 28 different plastics on spools. I guess I might buy my xmas filament from them instead.

BAMM settings for ColorFabb PLA/PHA

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with PLA/PHA from ColorFabb:

  • Temperature: 220-240C
  • Speed: 70mm/sec (faster = less jams / clogs)
  • Retraction: 1.5mm @ 20mm/sec (less retraction = less deposits)
  • Extruder tension: screws 0.0mm out (solid pressure)
  • Heated bed: 50C
  • Fan: full (to compensate for excessive temp required to prevent plugs)

 

Ultimaker - preventing the extruder from plugging

27 Apr

Ultimaker - preventing the extruder from plugging

If you have an original Ultimaker and have problems with the extruder getting plugged, I have a couple tricks that has saved me completly from plugs after implementing them.

After buying 7 spools of filament from Colorfabb, I was thoroughly disappointed. I kept getting filament plugs both at the top and bottom of the extruder. I contacted Colorfabb support and over a one month period, we tracked the problem down to two things. The filament were delivered in a cardboard box where small bits of cardboard cutoff from the production process, stuck to the filament. Every time one of these tiny bits of paper got into the nozzle, the paper burnt and plugged the extruder. The other thing is that the Colorfabb filament goes soft at a slightly lower temp than PLA from other vendors, causing it to plug more easily at the top if something is blocking at the tip.

Every time this happened, I had to disassemble most of the extruder and use drill bits and other tricks to remove the plug completely before trying again. Colorfabb has remidied the problem now and all their filament are now delivered in clean cardboard boxes with plastic bags around the filament. They also went really far in compensating me for the troubles I had, so I still recommend them and use them as my primary source of filament on spools. Great customer service always pays!

At the top of the extruder

If the entire extruder assembly runs too hot or you have a partially blocked nozzle, you can get plugs at the top of the extruder (between the peek and the white insulator). You'll spot these easily since you can't push any material into the bowden -> even if you unscrew the nozzle. Some time ago, I built an enclosure around my printer so I could do ABS without it cracking up from the material shrinking. The enclosure holds a nice, steady temperature but the increased temperature also increased the amount of plugs since the aluminium mount above the extruder got really hot and so did the peek part.

I've had plugs here on many occasions, but after adding a small fan that blows cold air onto the insulator, peek & aluminum mount I have not had a single one. You may have noticed that almost all new extruders (from makers like E3D, Makerbot & others) have a separate fan that is cooling the upper parts of the extruder. They probably do this because it's required for the new all-metal hotends, but it certainly helps on an Ultimaker too!

You can download the Fan mount and find instructions at my Youmagine page. It's very minimalistic.

At the bottom of the extruder

Plugs at the bottom of the extruder are much harder to prevent once they have happened, so making sure the filament is clean takes you a really long way in this regard. Just print a copy of this filament cleaner, cut off a bit of foam and place it where the material goes into the extruder.

Use these two tricks and you'll probably never ever get a plug again. I havent! yes

Filament review: Colorfabb XT

27 Apr

Filament review: Colorfabb XT

I've had a few really hectic months with a crazy amount of client projects. Hopefully that'll manifest itself on my bank account, but this weekend was my first few days of calm in two months. Time to play with the 3D printer again and experiment with one of my favorite filaments - ColorFabb's XT!

ColorFabb XT has been one of my favorite materials for a long time. In terms of properties, this PETG is sort of a crossover between PLA and ABS. As opposed to PLA, it is strong and quite flexible and it's much easier to work with than ABS since it barely shrinks at all. I've had varying results with it over time so I thought I'd experiment a bit with what are the best settings.

I first ran a series of tests to see how it's affected by speed (A), flow rate (B) and temperature (C).

I started with a base of 50mm/sec / 235C and the output looks good at both 50 and 100% of that speed. As soon as you go above, you'll see the pillar becoming less transparent. This is due to small bubbles of air and indicates that it's not feeding enough plastic through the extruder. This could be compensated somewhat by increasing temperature, but it seems that 60mm/sec is about as fast as I can go. When it comes to flow, the output looks good even at 90%, but at 80% it suffers (as expected). Nothing really interesting there, and also not when it comes to temperature. The 220-240C that is printed on the box the filament arrives in, looks quite correct.

Transparency

One of the things I really like about XT is it's transparency. You can't really make it fully transparent, but you can get some very nice effects by calculating your model to have walls that are a multiple of your nozzle size. In the image below, you can see how thickness affects transparency.

The wall thickness is written below the different wall segments. Opacity is quite good when holding the object close to the XT, but as soon as the distance is increased opacity suffers. The upper piece is a shorter model with the same thickness, but it's standing upright. What is interesting is how much the slicer affects transparency. I'm using Cura 14.01 for slicing and it constantly calculates the feed rate for infills incorrectly. To get enough material when filling 100%, I have to increase the Flow Rate to 160%? This must surley be a bug in Cura, but you can work around it by setting the Shell Thickness (= # of outlines) to a very high amount.

Another observation is that you will get the best transparency when you have long, straight lines. Curves & corners will automatically give you less transparency.

A couple tricks and a breakthrough

A hot tip if you get blobs or threads on the walls of your model, is to turn off Combing. This will force retraction on all moves and if your settings are otherwise correct, you'll completely remove the blobs. Another tip is that if the first few layers look good but the object then looses transparency, you can often save things by just slowing down a little as in the image below.

The biggest breakthrough I had in getting the XT to become clear, was after suggesting that Cura did not deliver enough infill. Daid (the maker of Cura) was quick to dismiss this possibility and I spent the whole evening doing more tests. After some cross-comparing with transparent PLA, I realized that Daid was completely right - no errors in Cura:

The first two of these are PLA and the last one is XT - otherwise using similar settings. Why was the XT so much less transparent? There were no difference? I then understood what the problem was.  To get XT fully transparent - you cannot use the fan!

In the image below the first one (A) was printed with the fan turned off until starting on the walls of the box. The second (B) is the best I could do with the fan turned on. The third is the reason I had the fan on - unless the fan is on, you'll get small blobs along the wall (C).

This is easy to solve however - Cura has a brilliant plugin-system that can turn the Fan on after either X layers or X millimeters of printing. Now, these boxes come out nicely every time!

So my magic settings for getting ColorFabb XT as transparent as possible - 35 mm/s, 235C, 105% flow & no fan for the transparent area. If you have a heated bed - crank that up as well as it'll help the layers blend by keeping the XT as hot as possible, so it blends better the next time the nozzle passes. Then you can crank up speed to 50 mm/s and turn on some careful fan cooling.

The reason I played around with this was to make a cutlery basket for my kitchen. Below you can see how it turned out and you can download and print the model here.

Heated Build Chamber for Ultimaker

25 Oct

Heated Build Chamber for Ultimaker

No - I'm not giving my Ultimaker away as a fancy wrapped gift in the image above. I'm just working around the most stupid patent ever granted in regards to 3D printing. Printing with ABS has one core problem - it shrinks when cooled down by almost one percent. This will cause all printed objects to have clearly visible cracks along the edges where the tension is the highest. It is very easy to solve the problem, but not without breaking a patent that should never have been granted.

Working around the Heated Build Chamber patent

It's incredibly easy to make a heated build chamber on the cheap. In my case, I used cheap oven bags from my local convenince store as suggested by Andrey on the Ultimaker forums. You just unwrap the backs, cover open surfaces and tape it in place. It takes some time to cover it all up, but it creates a fully working Heated Build Chamber. The oven bags are flexible enough to not break and they have no problem withstanding the heat.

Heated Build Chamber solves ABS cracking in 3D printing

I have now printed several ABS models using this method and I get no cracks in the surface at all. I also measured the inside temperature and without overdoing the tape along the oven bags, I can easily maintain 60C inside the printer - enough to prevent cracks. It is also important to let the object cool slowly after printing, so I just let the machine stand there until it's cooled to about 30C. Works like a charm and given that we have had ABS plastic since the 1950's - it should be fairly common knowledge that ABS needs to be cooled uniformly and slowly to prevent cracking and warping.

The patent and the problem with it

In June 2000, the company Stratasys was granted a patent that covers pretty much any way you can think of to cover your 3D printer to maintain a constant temperature as the object is built up. This idea did clearly not originate from Stratsys. It was common knowledge in the polymer business. However - Stratasys applied for a patent on this in regards to their already patented FDM printing process and they got it. The biggest problem with this patent is that it prevents you from doing what is obvious. It should not be possible to patent something obvious, but Stratasys managed to do so anyway.

So, patent US 6722872 effectively prevents ANY other firm from creating a printer with an enclosure around the printer that prevents ABS plastic from cracking up. They can of course contact Stratasys to license this or any of the 900+ patents that Stratasys holds. I do not know what terms a small scale 3D printer manufacturer would get, but I doubt it will be interesting to them. Just looking at the list of patents that Stratasys holds makes you cringe. These ideas won't be available to the general public until the patent expires in 20 years.

Why is that a problem then? My best illustration for how patents PREVENT innovation is looking at the RepRap family tree. The original FDM patent was filed by S. Scott Crump in 1989. Before the patent expired, there were only the Stratasys models as well as a few licensees. Just look at what happens in terms of diversity as soon as the patent expires! There's now more than 500 different 3D printers based on FDM out there. Now there's REAL innovation happening where crazy ideas are being tried out that Stratasys never persued like delta-printers and even more excotic ideas. That's not the biggest though. The price has come down from several hundred thousand dollars to below $300 for a machine that produces comparable quality. That alone should tell you quite a bit about how Stratasys has been milking the original patent.

Despite the patent having expired, we still cannot use the term FDM (Fused Deposition Manufacturing) since this is a trademark of Stratasys. Due to this, the RepRap project has come up with the definition FFF (Fused Filament Fabrication). Other patents are also attached to the FDM patent, preventing the full potential of 3D printing to be realized.

Can I break the patent?

Yes, but you cannot make a business out of it. In Europe, anyone is free to break patents like this as long as it is for personal use. In other words - you can break the patent, but you cannot sell a kit that allows you or others to break it. This previous weekend I was told that this is not the case in the US, but I have not been able to find good info on it. Please post links in the comments if you know more about US patent litigation and enforcement against individuals.

 

Promoting 3DP

11 Sep

Promoting 3DP

It's great fun when your hobby gets exposure. Walter and I are doing our best to tell the world just how cool 3D printing is. For Oslo Mini Maker Faire, the national broadcaster did a full 15 minute feature on Walter (my son). He'll soon be in an article in Magasinet/Dagbladet as well and today it was my turn.

During the last 3DP meetup at Bitraf, we got visits from a couple press outlets. Liam, Ketil, Elias and myself was interviewed and it took quite a chunk of the first day. The first to surface of these were a 2 page article in the magazine "Hjemme PC". Tonight, the TV show called FBI (ForBrukerInspektørene) had a nice segment on 3D printing as well. The main segment was from the Meetup, but as a fun side-note - the printer mentioned initially (that had some problems printing a good iPhone cover) was fixed a few days later by Ketil.

If you want to check out 3DP and are nearby Oslo mid October, feel free to drop by the 5th 3D Printer Meetup!

( Image credit/facsimile: NRK1/FBI )

3D Printer meetup #3

09 Mar

3D Printer meetup #3

Last weekend, I organized the third 3DP meetup in Oslo together with @kefir from reprap.no. Quite a good turnout of people and 14 different printers there. My two favorites were the Adapto printer that is using pretty much only parts that are avilable in normal hardware stores. How's that for RepRap? The other favorite were the two Rostock printers being built by two AHO-students. Very cool to see these in "real-life" and I could even help a tiny bit so that was fun as well.

The next meetup should be some time in May and I'm REALLY looking forward to see Johan's DuoHex machine! It has one of the smartest RepRap designs I've ever seen, using Hexagonal rods to drive a dual extruder design. Below is a short video showing the different machines at the event and here's some nice pictures that Kjetil took.

Heated Build Platform (Take 3)

23 Sep

Heated Build Platform (Take 3)

Some months ago I added a Heated Build Surface / Platform to my Ultimaker and after getting the power supply right it's been a great addition to a already good printer. I can now switch between ABS and PLA print materials without any problems but overall the setup has felt a little "flimsy". I didn't know what to do with it until recently.

A couple weeks ago, I organized (what I think is) Norways first 3D Printer meetup and it was great fun to see all the different printers present. Mendel, Prusa, Huxley, Makerbot TOM, MB Cupcacke, a huge BFB Touch as well as two Ultimakers was on display and about 38 ppl came to watch. The initial idea was to just meet up with a few ppl from reprap.no, but given the general interest and this being set up through Bitraf/Meetup a lot more ppl came to see.

Looking at the printers and talking to others I started thinking about swapping out the glass surface for an aluminium surface. My architect friend Jim commented "why do you use glass? It basically resists heat?" and then William (that also has an Ultimaker) said that he had access to cutting aluminium at his school... A week later he had it ready. This weekend I set it up and I can totally reccomend using Alu over glass as a surface!

My new aluminium surface heats up faster and distributes heat much more evenly. Wheras glass would shatter from thermal stress if it was bigger than the (20 x 20 cm) MK1 PCP heater, the aluminium surface distributes the heat MUCH more evenly. This allows me to use the full 21 x 21 cm of the Ultimaker - a very nice bonus.

Below are a few images of the new setup and how I did it. Click any image to zoom.

The 22 x 22 cm aluminium plate is 5 mm thick. I first taped the MK1 PCB on top, marked the holes and then drilled the four 3mm holes. I also counterbored with 5.5 mm so that the top of the screws would be flush with the surface.

I use four 16 x 3mm screws and a nut to hold the PCB tightly against the aluminium sheet. I then stick these four screws into matching holes in the plywood surface that I use to adjust the height/levelling.

Here you can see the screws that I use for the levelling. They go through the "stock" Delrin pieces, but I've swapped the direction so I adjust them from below. this makes it much easier to tweak on the fly once the print has started. After applying a fresh coat of kapton to the bed, I printed the hollow pyramid that use for calibration and it turned out great. The price for such a sheet of 5mm aluminium is also not very scary. I'm paying something like $35 for mine, excuding the cutting. In other words - I now have both retraction and the build surface pretty much under control and a V2 nozzle is on it's way too.

Below is a picture of my extruder-drive designed by Bertho  It's a really great mod that does wonders for retraction, but I still have some issues with filament grinding and I need to solve this 100%. I this I'll look into some Wades extruder-feeders next to see if that can help the ever annoying problem of material grinding...

Heated Build Platform for Ultimaker

19 Jun

Heated Build Platform for Ultimaker

Note: updated description available here! While this is written for the Ultimaker, it should also work the same for any RepRap printers with similar RAMPS electronics.

One thing I disliked with using a Makerbot was it's dependance on printing with ABS plastic. ABS comes from fossil fules and is thus a limited resource. PLA usually comes from Corn and is thus fully renewable and to some degree also biodegradable. This was one of my main reasons to get a Ultimaker in the first place, but then it dawned on me that the 60 degree celcius melting point for PLA was going to be a problem for many of my projects. I had to make my Ultimaker capable of using both plastics: PLA for prototyping and ABS for lasting models.

Why

When you are printing with PLA, all you need is some blue painters tape to print on. ABS however, won't stick to that. In addition - ABS requires that you keep the model warm while printing and ideally it should be allowed to cool off slowly to avoid cracks due to the material shrinking. How warm the heated build surface should be will vary a little based on the plastic, but I found these tables in the Makerbot Wiki a good reference. 110-120 celcius seems to make the ABS that I use stick well.

You can also use a heated surface for PLA, but then you keep it at about 70 degrees celcius. A nice plus when printing PLA on a heated surface is that it requires virtually no force to remove the model once the surface has cooled. What I needed was a Heated Build Platform (or HBP for short).

What and Where

How does one make such a thing? The RepRap wiki has many suggestions but after reading through all the links, there was one design that really appealed to me. It's basically a PCB that barely has any components, but rather lots of copper. When power is applied to the PCB, the copper turns hot - just like in an electric oven or a hair dryer. 

This PCB was designed by Josef Prusa and it's a perfect size for the Ultimaker (20 x 20cm). It also has a feature that I appreciate - it's made for 12 volt operation so no need to mess with AC electricity that could kill you! There are many similar methods used in various industries today and if I didn't want to use 230v, I'd probably get the SRFG-808 from this site (GBP 44).

Josef's design is called MK1 but the wiki also contains an alternate version here is a derivative version with a hole in the center. This one is called MK2. These both work the same, but there's really no need for the hole in the middle. This description should work for both though. After reading some warnings and sad stories from people that bought "cheap" PCB copies on Ebay, I decided to get a MK1 from a reputable supplier that would also give a little back to the creator of the PCB. I didn't find any good tutorial on how to set the heated bed up, so I figured that I'd write how I did it for others to find.

The nice thing about shopping from companies like Ultimachine is that they know what else you need. I also picked up a 100k Thermistor with PTFE sleeving from them to measure the temperature. I also picked up some 100mm Kapton tape for covering the print surface. You can also use thermistors with 10 or 200k resistance or a thermocouple based on AD595. Thanks to Daid's great Marlin Builder, you can adjust your Ultimakers firmware to reflect the correct hardware. Speaking of Daid - if you're not using his Cura software for your Ultimaker - you're missing out Big Time. To me it's been the difference between a good purchase and a bad one!

The Power Supply that comes with the Ultimaker cannot drive both the machine and a heated bed. Due to this, most others have gone the path of adding an additional power supply. Some have even replaced the existing one, but due to the limited space beneath the Ultimaker I had a hard time finding one that could both fit inside as well as provide a decent airflow to keep things cool. What I ended up getting was an external power brick that could deliver 12.5Amps of 12 volt. The PCB only pulls 10A maximum so I figured that would be sufficient. Having two power bricks isn't "sexy", but it does not require any big changes to the Ultimaker's stylish wooden body and it does not add more noise. Also - they had one at my local computer supply store, so I could just pick it up. It's a little pricey at GBP100 / $150 but I still like the solution.

So I had the heating element, a way to power it and a way to measure the temperature. Now I just needed a way to turn it on and off when required. I was thinking of building my own solution, separate from the Ultimaker. The Streacom PSU had both 5v and 3.3v so I could easily add an Arduino Mini to control the heated bed. I would need a screen or at least one 7-segmentd display, some buttons for control and with this I could even pimp my Ultimaker by letting this control some RGB LEDs. Yeah. That's what I'll do! I ordered a bunch of components from Adafruit and Sparkfun, but as I waited for these it started to annoy me that I couldn't combine this with the Ulticontroller.

I started digging and it turns out the Ultimaker PCB had lots of what was needed. There's a connection for the thermocouple and a PWM output with a solid MOSFET... I wonder if that couldn't drive a standard relay for a car? I picked up a 30 amp relay at my local car supplies and it worked like a charm with the 19 volt output of the Ultimaker. I got great help from this Instructable measuring the Relay. The relay cost $6.50 and I also got a nice socket for $4 that I could use for simple mounting and replacement (if required).

This is how the end result looks and below is a tutorial on how to do this yourself.

Bill of Materials

Here's the list of components I've used:

  • MK1 PCB. See RepRap wiki for suppliers. ($50 from Ultimachine)
  • 100k Thermistor ($2.75 from Ultimachine)
  • Streacom 150 watt external PSU ($150 at my local PC store)
  • 360 watt industrial type PSU from Ebay ($50 with shipping)
  • Relay + relay socket with cables. Make sure it's a 5-pin one, so it's both open/closed. ($10.50)
  • ATX 24 to 20 pin conversion cable ($8 at a local computer store)
  • 25 x 25cm plywood piece, 10-12mm thick, as flat as possible ($2 at a woodshop)
  • 24 x 24 cm sheet of 4 mm glass with 4 holes spaced 209mm apart ($30 at my local glass-shop)
  • A 4.7k resistor
  • A few 3mm o-rings (rubber gaskets) that fit the holes in the glass sheet
  • Four 4-6cm, 3mm bolts
  • Some 3mm nyloc nuts, washers and other spare parts that came with your ultimaker
  • Kapton tape

Tools

  • multimeter
  • basic soldering kit
  • Drill
  • Having an Ulticontroller is a huge plus for reading the temperature

Alltogether, the cost for my heated bed was about $150. I also could have saved a little by not getting holes made in the glass but rather use bulldog clips like Josef Prusa did. That would have saved a few dollars as well, so the total cost could have been as low as $100. Also note - these prices are from Norway ( = everything is expensive) so your bill will probably be lower than mine.

How

So - how to put this together then? It's not hard at all and I've also made some custom 3D parts to make it easy to mount the hardware.

1. Print the adjustment screw pieces

Printing these before removing the old build platform will save your fingers later on!

2. Drill 8 holes in the plywood square

Make 4 holes (3mm) that match the position of the adjustment screws of the original build platform. Then make 4 holes that match the position of the holes in the PCB. Make sure you drill all these very precisely or it won't fit.

3. Remove the old platform

Remove the acrylic and unscrew the screws. Save the screws as you'll use these later.

4. Mount the new adjustment screws

Take one long screw, one nyloc hex nut and one plastic screw-handle (eye-shaped) and put these together. These provide a solid adjustment screw for the bed and the screw-handle makes them much easier and precise to use than the hex-wrench. Once all four are put together, screw them into the delrin holes - but this time screw them in from the bottom. Using an electric screwdriver/drill is recommended. Tiresome!

5. Mount the PCB on the Plywood

For this, you can use the old "adjustment" screws. I put a hex-nut between the Heater PCB and wood, and another hex above to keep things in place. On top of this, I added a washer. In the picture below I've also added the springs from the old setup. Don't do this. It was just an experiment. O-rings are smarter.

 

6. Mount the Thermistor

It is nice to have a way to measure the temperature before you hook the Heater PCB to it's power. There are two things to do here. First you need to solder a 4.7k resistor on the Ultimaker's PCB. Unscrew the Controller PCB and take it out of the machine. The resistor should be added where it says R4 on the Controller PCB.

Next, make two wires that are about 70 cm long. These should be of the standard, thin type used in the rest of the machine. Guide the cables down through the rear, right cable duct. Connect these to the outer two pins on the connector marked "Temp 3" (as shown in this picture). Next, put the fan-thingie back on the Ultimaker Controller PCB. If you forget this, you'll easily destroy it.

Connect the other end of the wires to the Thermistor. I used a 2-pin terminal block as the thermistor can be hard to solder due to it's ability to withstand high temperatures. Now it's time to turn on the Ultimaker and test it! To do this, you'll need a custom firmware version. I assume you already use Cura for slicing and printing your models? Then you already know that Daid makes some great software! Making the custom firmware is really easy with his Marlin Builder script. Be careful to not adjust anything you don't know what is... Under "Heated bed temperature sensor", select the sensor you got. There are several 100k thermistors in the list, but if your isn't listed (or even marked in any way) just go with the "100k thermistor" option. If you have the Ulticontroller, check that one off the list as well and click the "Build Marlin" button.

At the top of the page there will now be a download link for a ZIP with the windows install file (that I used), as well as the .HEX file itself. Once the firmware is updated, it's time to test! If you have the Ulticontroller, you should now see another temperature reading and if you touch the temperature sensor, the display should change to reflect that you are (hopefully!) warmer than your surroundings. If you want to test it at higher temperatures, stick the thermistor to the printers extruder-head and set a new temperature with the Ulticontroller.

PS: Don't worry about the heat damaging the thermistor. It should be rated for more than 300 degrees and you should not go above 240 to avoid blocking your print head with burnt filament... Just test that the temp is fairly correct up to 110-120 as that's the highest you'll need to go.

7. Mount the relay

Solder a couple of wires (about 80 cm) to the heater PCB. According to this chart, these cables should be no less than 1.3mm thick to carry 10 amps safely. I used 2mm to be on the safe side, but that's probably not required. Guide the cables down through the rear, right cable duct as you did for the thermistor. Don't pull all the cable to the bottom as you'll want to be able to move the Build platform up and down without pulling the wires.

Next up is the Relay. I used an automotive relay since I know that they are made to withstand a lot of power and they are dirt cheap. Any relay rated above 10A(mperes) should be fine as long as the voltage is more or less the same as the 19v the Ultimaker will output. Autos use 12v and are rated for 30A so that should work for most relays.

Measure the relay according to these instructions and make a note of what color the different cables are and what they should do. If you got a relay like the one I got (5 cables), there will be_

  • Two cables where you apply power to close the relay (connected to the Ultimakers output)
  • The two cables that will be connected when the relay is closed (external power goes through here)
  • One unused cable

In the linked tutorial, the first two are referred to as COM and NO. On the relay that I was using, these are referred to as 86 and 85:

Between these, you should be able to measure a connection but the resistance should not be very high. Connect these to the Heated Bed output, close to your Ultimakers power jack.

On my relay (see below) the pin marked 30 is common and pin 87a is the normal position. When I measured these and found a fairly high resistance (as indicated in the tutorial). That meant pin 30 amd 87 should connect when the relay became energized. So by simply connecting one of the cables for the heated bed through pin 30 and 87, the Ultimaker would toggle power on/off as required.

8. Prepare the ATX connector

It's not much that you need to do with the power supply itself, but you'll need to tweak the ATX conversion cable a little. Start by cutting off the 24-pin side of it and then remove the wires you don't need. Since the PSU has some amperes to spare and it's easy to keep the 3.3 and 5v cables, I saved some of these in case I want to add an Arduino for some custom lighting or something. According to what I've read, the pins in the ATX connector are rated for 6A each, so to safely use 10A I connected two grounds and two 12 volt together. 

Yellow = 12v, red = 5v, orange = 3.3v, black = ground (ref)

9. Testing time

Make sure you re-attach the fan over the Controller PCB and then flip the Ultimaker over to normal position. Now you can test if you connected it correctly by setting the heated bed temperature to something above room temperature.

If you are using the Ulticontroller, just select the Heated bed from the menu. If you don't have the Ulticontroller, you will need something that can connect to the printer and send it commands. Both Printrun and ReplicatorG can do this. In Printrun, there's a separate window for entering commands directly. In ReplicatorG, you just make a new file, type the command into the gcode-tab and then send it to the printer as you would when printing. The command to send is:

M140 S70.0

This should set the temperture of the bed to something near 70 degrees. When the Ultimaker reads the Thermistor to be too cold, it will apply power to the Heated Bed output and close the relay. When the relay closed, I could measure a decent resistance from pin 30 to 87, but no longer from 30 to 87a. The connection was confirmed! My next step was connecting it all to the Heatbed PCB, place the thermistor on the Heated bed and test the complete setup.

Note: Since 1.5.4 of the electronics, the Ultimaker has a 55A MOSFET on the heater connection. This should be sufficient to switch the power to the bed directly, but I don't know enough about electronics to confirm this. Using a relay is within my scope of knowledge, it's totally clean and also separates the two completely in the case of an error. It would be great if someone wiser than me could comment if direct switching is now possible!

I tested thoroughly and measured with an IR thermometer what components became hot as the bed heated. On the tiny PCB that distributes and converts power became hot after 3 hours continous heating. It's the square, black component that becomes warm - about 70 degrees. I made a mounting bracket for attaching it to the bottom of the Ultimaker and on this one, I added screw-holes for a 20mm PC fan. These can be bought in any computer supply store. They operate at 12 volt and it keeps the ATX connector at room temperature even when the bed is constantly on for 10 hours or more.

10. Mount it all on the Ultimaker

Once you are sure the electronics work as intended, you can wrap up the build. First, secure the electronics in place beneath the Ultimaker. For this purpose I've made some more printed parts. Make sure that the holder for the ATX-plug-holder is printed in ABS and not PLA (so it handles heat better). You just slide this one onto the connector and screw in place a 20mm fan. Connect the fan directly to the 12v lines on the connector, drill the one missing 3mm hole under the Ultimaker and fasten the holder with some of the 3x10mm spare screws that came with the machine as well as some nylock nuts.

Next, mount the power jack. This requires some drilling to get perfect, but I'm quite happy with the result.

When this is in place and the cables have been adjusted a little, it doesn't look too messy beneath:

You can see the connections more clearly in this image (click for full rez):

I mounted the 4.7k resistor on some header pins to see if I could get more precise temperture readings by tweaking the resistor values. In the end, I ended up going with the 4.7k anyway so I should probably remove the headers and solder it permanently.

Put the plywood/pcb on to the adjustment screws. Cover the glass plate with kapton tape and put it onto the PCB. Adjust the height of the Heater PCB screws, so the top is flush with the glass surface. Add o-rings (rubber gaskets?) between the 3mm screw and the glass. This ensures that the glass lies steady, but still can expand a bit as it gets hot.

Next we need to make sure the bed is entirely level. The standard rule about being able to pull a sheet of paper between the print head and the surface applies. Move the print head around the entire surface to make sure it does not touch the glass/kapton surface.

Adjust the length of the wires for the Heater PCB and the Thermistor. Make sure to leave some centimeters of wire so that the platform can move all the way up/down without pulling the cables.

That's it. Set the temperature of the bed depending on your plastic type and print away!

The result

The Heated Bed works just as intended and I'm very happy to have it all working. Before doing this, I thought that the constant clicking of the relay would drive me crazy bt it's really no problem. The printer itself is so loud that it's merely a drop in the ocean. The setup has been working non-stop for almost two weeks now. For PLA printing, it's simply fantastic. Models stick like glue when the platform is at 70 degrees, but come loose very easily when the platform cools off.

For ABS, it works but it's not perfect. It takes about 10 minutes to get up to 100 degrees. This is decent, but quite a long time. To get to 110, it's even longer and I can just barely go beyond that. The thing is that I need the bed to go to 110 and maybe also 120 for the ABS to stick properly. Now, it works fine for models that have a large area of contact, but smaller models often come loose since the plastic isn't sticking well enough. Due to this I'm now experimenting with closing the gap around the build surface using high-temperature silicone. This looks good so far, but I'll update here once I get to test a little more.

Update June 23rd 2012:
Closing the gap around the Heater PCB gave no measurable effect! Have to say I'm a bit stunned by that one. It takes just as long to get up to temperature and it's just as hard to go higher. I guess that means that my Power Supply is too weak. I'll test this with a computer PSU and update here later.

Update July 25th 2012:
Tried with a 450 watt PSU (12V/16A) and found no noticable difference. Could it be that I need to bundle the two 12V lines? Thinking aloud: 12V * 16A = 192 watts. Multiplying this with two seems like an idea, but I'll need to find documentation on how this PSU (KDM-1UFX425) is built then. I don't want to start a fire...

Update 3 August 2012:
Turns out that my idea of maintaining some distance between the glass and the PSU wasn't such a good idea after all. When testing with a different PSU today, the glass cracked since the glass was bigger than the PCB and thus wasn't heated equally. I have a spare 20 x 20 cm glass that I'll fix to the PCB with bulldog clips like all others do. I have those already.

Update 5 August 2012:
Turns out I simply did not have enough power. Instead of using the 120 watt Streacom PSU, i will be using a 360 watt industrial type PSU (12V / 30A) that I got from Ebay for about $40 (plus shipping). You can see this PSU in the image below. The drawback of this one is that I sort of have to deal with 220 volt, but it's quite well protected so it's not scary in any way. I will also have to print some feet for the Ultimaker before mounting this permanently as it's a little too tall (5cm), but it'll fit nicely just behind the front of the machine. This PSU also has the extra power to drive LED's and such so I can now "pimp" my Ultimaker a little more wink

 

My new Ultimaker 3D printer

28 Apr

My new Ultimaker 3D printer

After playing with my friend Jim's Makerbot for some time, I realized that I simply had to have one of these. However - having a moving build platform really limits the speed and usefulness. I researched what machines were available and they all had similar limitations. Either they were too flimsy or had a moving build platform. Then I found the Ultimaker. It has a build platform that only moves up/down. The X/Y axis is moved by double belts pulled by the same axis and it can run at crazy speeds. The material feeding system also looked a lot better than on the Thing-o-Matic. I hit the buy-button and got the printer only 20 days later - not bad given that others have more than 6 weeks lead time.

I read that it would take a full day to assemble it, so I prepared my family that I was going to be somewhat busy one of the days ahead. The package stood idle while I waited for an opening in my work schedule. It's not that often that I buy "toys" that cost €1200 so I figured that I wanted to combine the build experience with another hobby. While building the printer this friday, I did a timelapse (still to be edited) of the whole build process (like many others).

Building it

It really took a full day. I started at 9:00 and ended at 23:30  - without having printed a single thing. I could have done it in 3-4 hours less, but there were some issues while putting it together. I'm also a family man so I also set aside some time (not much) for dinner and playtime with the kids. Putting together the case and endstop switches took about an hour. I then moved on to the X/Y motors, belts and pulleys (about 2 hrs). The most elaborate part is the print head and X/Y axis. This took almost 3 hrs. The build platform came next and that took about one hour. Next was the material feeding system and that was my first problem.

Incorrect parts

Before complaining, I should add that the people at Ultimaker are hobbyists that put together a good machine and now sells it commercially - with a BETA-tag on the name. The machine sells with a disclaimer that says that this really is a kit and you must be sure that you have the skills required to assemble it yourself. Interest has been crazy and they're working hard to scale up their operation to handle the interest. The problem is that the product is still very much under development and it's nowhere as polished as Makerbot Industries that has been in business for quite some time (Last number I saw for Makerbot was 80 fulltime employees). The Ultimaker team surely has growing pains and getting the logistics right is probably a solid learning experience.

So - what went wrong? Apparently they didn't have the correct Hex nut's and washers available and someone made up a quick solution. However - they didn't test this and there is no way one could mount the supplied washers/nuts with the special hobbed bolt so that it would move the print material forward. The washers supplied were simply too big, so they prevented the ball bearings from rotating. After some testing and thinking, I popped off to a local hardware store and picked up some washers with the same 8mm inner dimension, but with a narrower outer dimension. Worked like a charm!

Mounting the electronics was easy and at around 22 I was ready to print and then...

Nooooo!

I could not believe it when I saw it - they had forgotten to add the stupid cable with my power supply? Normally that wouldn't be an issue, but they use this stupid kind of grounded plug that is shaped like a clover. After some searching, I called around and went off to my dad to pick one up.

I plugged it in and was told that I had to update the Ultimaker firmware from version 0.1 to 1.0. It's easy-peasy it said - just select it in the menu. That didn't work but I still wanted to try printing... I loaded up a model in ReplicatorG and BRRRRRRRR - the steppers slammed the print head into the edge with no sign of stopping. Ok. That's enough for one day I thought and went to bed.

What a difference a day makes

The next day I realized that they have swapped the markings for where to connect the X-axis endstops, so that solved the problem ending the day before. I then tried uploading the firmware to an Arduino Mega I had lying around and that failed too. Maybe it was because I used a Mac? I installed ReplicatorG 034 on the PC as well and had the same problem. Hmmm... Maybe I shouldn't use the bleeding edge version and rather try the older 025 build? That worked, so now update using old software and print using the newer version. Ok. I can live with that, but it surely would be great if the Ultimaker Wiki told me in the first place...

Today I've been printing all morning and eve, but I'm not really at a point where I have something solid to show. I can't really bend ReplicatorG to print anything other than the test-cube and it can only print it at 1x speed. If I try to print it at 200% speed, the build just stops after a relatively short time. No warning, no nothing. It just stops? (Update: this is a bug in USB/serial comms on my Mac. It works flawlessly on a PC so now I'm using that) Loading other models defaults them to the front, left corner no matter where I place it in the program. I'm currently experimenting with using Slic3r to make the GCode instead. It looks MUCH more solid but on all bigger models I have a problem with the build just stopping? I think I need to try another firmware.

Overall, I'm incredibly impressed by how well the machine is built. Every little detail like the build surface leveling, the nice cable ducts, how all moving parts are really solid, the material feeding, the precision laser cut parts and certainly the speed and resolution that the printer can produce compared to the Makerbot Thing-o-matic. I'm working on a short post highlighting the differences between these two.

Some lessons learned

So - I'm almost up and printing after 1,5 days. Not too shabby (given how much time others have used for simpler printers) and it was a great experience despite the hurdles. Here's some things I picked up along the way:

  • You'll need a wrench, a stanley knife (or similar), tweezers, a tiny screwdriver and some plumbers tape. Luckily I had that last one around, but I think the Teflon-version is probably better as I have a small leakage around my nozzle.
  • Improvisation is required - just as the disclaimer says "in some cases you can get better results if you have some improvisation skills"
  • Don't touch the Hot-end -> it is VERY hot so don't touch it (really!)
  • Makerbot really is more user friendly. With Ultimaker you'll be learning a lot you didn't know you needed to learn
  • Most Ultimaker users are PC people. While the Mac software exists, it's probably not too well tested so if you have a PC - use it rather than the Mac.
  • If you need help - the Ultimaker Google Group is your best friend, filled with good advice from nice people

Looking forward to further explorations in the days to come!